Service
Alot of things fall into play on this subject, or who you talk to personaly I change my mine every 5000 miles with delvac 1300 and two quarts of Lucas,along with a good check of driveline, if ive been doing alot of driving every 3000 if if had alot of idle time, Fuel filter I drain often and change every 10,000, along with checking all other fluids